In a wideband code division multiple access (WCDMA) system, a user equipment (UE) may be configured with one or more transmission technologies. For example, an R99 transmission technology, a high speed downlink packet access (HSDPA) transmission technology and a high speed uplink packet access (HSUPA) transmission technology. Uplink transport channels, that is, dedicated physical channels, of the R99 transmission technology mainly include a dedicated physical data channel (DPDCH) and a dedicated physical control channel (DPCCH); uplink transport channels of the HSDPA transmission technology mainly include a high speed dedicated physical control channel (HS-DPCCH); uplink enhanced dedicated transmission channels, that is, enhanced dedicated channels (E-DCHs), of the HSUPA transmission technology mainly include an E-DCH dedicated physical data channel (E-DPDCH) and an E-DCH dedicated physical control channel (E-DPCCH); a UE sends data to a network by using a configured transmission technology, so as to implement communication of the UE with the network; when transmit power for the UE to send the data to the network is relatively high, not only quality that the UE sends the data is affected, but also interference is caused to another user equipment and therefore, the transmit power of the UE needs to be controlled.
At present, a method for controlling transmit power of a UE is provided, which is specifically: determining transmit power of a DPDCH, an E-DPCCH, an E-DPDCH and an HS-DPCCH according to transmit power of a DPCCH and calculating total uplink transmit power of the UE according to transmit power that is of the DPDCH, the E-DPCCH, the E-DPDCH and the HS-DPCCH channel and that is relative to the DPCCH; when the total uplink transmit power of the UE exceeds maximum allowed transmit power, determining whether the UE is configured with an E-DCH channel of HSUPA, where the maximum allowed transmit power is a smaller power value of maximum output power corresponding to a power class of the UE and uplink power configured by a network for the UE by using signaling; if the UE is not configured with the E-DCH channel, reducing transmit power of the DPCCH, the DPDCH and the HS-DPCCH that are of the UE by an equal scaling factor; and if the UE is configured with the E-DCH channel, first reducing a gain factor of the E-DPDCH of the E-DCH, determining total uplink transmit power of the UE and determining whether the total uplink transmit power of the UE exceeds the maximum allowed transmit power and if the total uplink transmit power of the UE exceeds the maximum allowed transmit power, reducing a gain factor of the DPCCH of the UE and reducing gain factors of the DPDCH, the E-DPCCH and the HS-DPCCH that are of the UE by an equal scaling factor, so that total uplink transmit power of the UE does not exceed the maximum allowed transmit power.
It should be noted that a gain factor of a channel is a ratio of transmit power of the channel to transmit power of a DPCCH and when the transmit power of the DPCCH is constant, reducing the gain factor of the channel is equivalent to reducing the transmit power of the channel.
In a 3G network, circuit switch (CS) services are mainly responds for calls between user equipments, packet switch (PS) services are mainly responds for Internet access data of a user equipment, the DPCCH and DPDCH are configured to bear the CS services and the E-DPDCH, E-DPCCH and HS-DPCCH are configured to bear the PS services. When total uplink transmit power of a UE exceeds maximum allowed transmit power, in the prior art, transmit power of a DPCCH, a DPDCH, an E-DPDCH, an E-DPCCH and an HS-DPCCH is simultaneously reduced by an equal proportion, which may increase a frequency of CS service call drop, resulting in discontinuity of calls between user equipments.